Diagnostic Aids

WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Incorrect ratio codes typically indicate mechanical conditions with specific clutches, such as C3 and C5 for REVERSE range.
Incorrect ratio code could indicate a hydraulically failed solenoid. Observe DTC information for specific solenoid.
You may have to drive the vehicle in order to experience a condition.